Manometer with contacts having means providing for adjustable ranges



June 2, 1964 A. MARGERIE MANOMETER wn'a CONTACTS HAVING MEANS PROVIDI FOR AD TABLE RANGES F 1 July 1961 United States Patent 3,135,843 MANOMETER WITH CONTACTS HAVING MEANS PROVIDING FOR ADJUSTABLE RANGES Andre Margerie, 30 Rue Jacquart, Pantin, Seine, France Filed July 10, 1961, Ser. No. 122,831

Claims priority, application France Aug. 16, 1960 3 Claims. (Cl. ZOO-81.8)

The present invention relates to manometers.

This invention, which applies particularly to a manometer with a deformable vessel such as a Bourdon tube, provides a manometer including an element movable in correspondence with variations in the pressure of a fluid,

movements of the element resulting in pivoting of a multistepped cam, the manometer further including a pivoted lever biased into contact with a control cam of range to be measured by another cam'acting on the microswitch support, this cam being controlled by a knob provided with an indicator for the specific ranges of operation.

The accompanying drawing illustrates, by way of example, the application of such a device to a manometer with a Bourdon tube.

FIG.,1 is a plan view of an embodiment of the'apparatus, and

FIG. 2 is a separate view of the stepped sector cam on a larger scale than that of FIG. 1.

The Bourdon tube T is subjected to the pressure to be measured through a connection R onto which it is fastened. The free end of this tube is connected by a link B to the tail V of a stepped sectorcam S, pivotable about aspindle O. This tail' V is formed with a slot C permitting the angular movement of the cam to be adjusted as a function of the pressure.

The stepped sector cam S, shown separately in FIG. 2, comprises a succession of arcs about center 0 and with successively increasing radii in the clockwise direction, separated by inclinesE. There are as many arcs as there are pressure ranges to be measured; in the case of FIG. 2, four ranges are shown, going respectively, for example, from 0 to 0.5, from 0.5 to 2.5, from 2.5 to 5.5,

and from 5.5 to 10.0.

A microswitch 1 comprises a control lever .L, carrying at one end a cam follower D arranged to bear on the profile of the stepped sector cams.

The unit comprising the microswitch is pivoted at X and biased by a return spring F into contact with a pivoted cam G having the same number of regions as the steppedsector cam has of arcs of different radii. The spindle of this cam is integral with a control knob which comprises an indicator H movable relatively to reference indicia marked on the dial the distances of the successive steps of the cam G from its pivotal axis increasing progressively in one direction. Each of these indicia corresponds to a testing range of the manometer.

* 3,135,843 Patented June 2, 1964 ice Flexible leads connect the microswitchterminals to current supply terminals projecting outside the case of the manometer.

The apparatus shown in FIG. 1 does not include a pressure indicator needle, but such a member indicating the pressure on a dial could be added, driven by an appropriate mechanism.

The apparatus operates as follows: when the indicator H is set at the chosen indicium, 2 for example, the unit formed by the microswitch and its lever will occupy a position such that said micro-interrupter will operate when, under the action of pressure increase in the tube T, the stepped sector cam S moves in' the sense of the arrow 1 until the incline 2a of the cam, corresponding to the chosen reference, displaces the lever L and actuates the microswitch; at this moment the circuit is closed, and will remain so until the pressure drops to a value corresponding to the position 1a of the incline of the stepped sector cam S; in this position la the lever L will be able to swing sufficiently to make the circuit re-open.

The same action will take place in the various positions in which the indicator H is set.

Since the microswitch is set up as a reversing device, the order of opening and closing the circuit can be reversed.

I claim:

1. A manometer including a housing, a support within the housing, a pressure-sensitive movable element mounted on said support, means to apply to the element fluid of which the pressure is to be measured, a multistepped cam pivotally-mounted on said support, the steps being a at progressively increasing distances from the axis, means connecting the pressure-sensitive movable element to the cam whereby pressure variations cause pivotal movement of the cam, a lever pivoted to the support, a control cam pivotally mounted on the support, said control cam having a peripheral portion which gradually approaches the axis of the cam from one end of the portion to the other thereof, means extending from the housing for manually adjusting the control cam, means biasing the pivoted lever into contact with a step on the control cam so that pivotal movement of the control cam is effected to vary the inclination of the lever, and electrical microswitch mounted on the pivoted lever, a switch-operating lever extending from the pivoted lever and having one end bearing on the multistepped cam whereby the microswitch is operated by the multistepped cam at a step determined by the setting of the control cam.

2. A manometer as claimed in claim 1, in which the pressure-sensitive movable element is a deformable vessel.

3. A device as defined by claim 1 in which the said peripheral portion of the control cam is in the form of steps corresponding'in number to that of the stepped cam.

References Cited in the file of this patent UNITED STATES PATENTS 1,074,137 Schubert Sept. 30, 1913 1,290,928 Denison Jan. 14, 1919 2,420,282 Bowditch May 6, 1947 2,537,771 Lovett Jan. 9, 1951 2,540,444 Harland Feb. 6, 1951 FOREIGN PATENTS 423,495 Germany Jan. 8, '1926 

1. A MANOMETER INCLUDING A HOUSING, A SUPPORT WITHIN THE HOUSING, A PRESSURE-SENSITIVE MOVABLE ELEMENT MOUNTED ON SAID SUPPORT, MEANS TO APPLY TO THE ELEMENT FLUID OF WHICH THE PRESSURE IS TO BE MEASURED, A MULTISTEPPED CAM PIVOTALLY-MOUNTED ON SAID SUPPORT, THE STEPS BEING AT PROGRESSIVELY INCREASING DISTANCES FROM THE AXIS, MEANS CONNECTING THE PRESSURE-SENSITIVE MOVABLE ELEMENT TO THE CAM WHEREBY PRESSURE VARIATIONS CAUSE PIVOTAL MOVEMENT OF THE CAM, A LEVER PIVOTED TO THE SUPPORT, A CONTROL CAM PIVOTALLY MOUNTED ON THE SUPPORT, SAID CONTROL CAM HAVING A PERIPHERAL PORTION WHICH GRADUALLY APPROACHES THE AXIS OF THE CAM FROM ONE END OF THE PORTION TO THE OTHER THEREOF, MEANS EXTENDING FROM THE HOUSING FOR 